摘要：英语中的句子，一般情况下都保证有谓语动词，如果再有动词的时候，就必须考虑非谓语动词，动词不定式就是非谓语动词之一。to do 主动结构，to be done是被动结构。下列情况，只用动词不定式。
英语中的句子，一般情况下都保证有谓语动词，如果再有动词的时候，就必须考虑非谓语动词，动词不定式就是非谓语动词之一。to do 主动结构，to be done是被动结构。下列情况，只用动词不定式。
一，常用不定式做主语
To get to school takes me twenty minutes. （谓语动词是takes，to get to school是动词不定式做主语）It takes me twenty minutes to get to school. （it 是形式主语，to get to school真正的主语）二，常用不定式表示原因，目的和结果
I'm pleased to meet you.（原因）My father will go home to visit my grandmother.（目的）They ran as quickly as they could to catch up with us.他们尽快地跑，目的想赶上我们。（目的）The old man was too angry to speak.那个老人太生气说不上话来（结果）三，常用不定式做及物动词的宾语，表示将来的动作。
I want to be a policeman.They hope to meet in Beijing.My uncle would like to work in the company.The house needs to be repaired.这房子需要修理了。These books are so good that I can't decide which one to buy.四，常用不定式做宾语补足语。
My parents told me to get up early.My teacher asked me not to arrive late for school.I make the boy clean the classroom.（使役动词后面不要to）We saw them sing the song.我们看见他们唱完这首歌的。（感官动词后省略to表示完全过程）五，用动词不定式做定语
He is always the first to come to school.他总是第一个到校。It's time to go to school.Let's have something to drink.五，在特殊结构中
The scientist seems to be ill. 这位科学家好像生病了。To be honest, I don't like the film.说实话，我不喜欢这个电影。The book is said to sell well.据说这本书很畅销。来源：郑老师KMYYZY
